The tire vulcanizing machine is provided with upper and lower metal molds and a bladder expanded and contracted by supplying and discharging the fluid, and is structured such as to vulcanize and mold a green tire by pressing the bladder expanded by supplying the fluid to an inner surface of the green tire which is set to an inner portion of the metal molds (see Patent Documents 1, 2, for example).
(Patent Document 1)
    Japanese Patent Application Laid-open No. 2001-30270(Patent Document 2)    Japanese Patent Application Laid-open No. 2002-120228
The fluid is supplied and discharged to and from the bladder through fluid supply ports and a fluid discharge port formed in the fluid supply/discharge head. In a prior-art fluid supply/discharge head 5a, for example, as shown in FIGS. 5 and 6, fluid supply ports 71 and a fluid discharge port 61 which are open to face an inner portion of the bladder are formed on the same plane.
FIG. 5 is a vertical sectional view of a prior-art fluid supply/discharge head 5a and FIG. 6 is a sectional view taken along a line C-C in FIG. 5. On the same plane of a head block 50, unequally spaced six fluid supply ports 71 and a fluid discharge port 61 are formed and four fixing bolts 60 for mounting the head block 50 to a bag head 4 are provided.
If the fluid supply ports 71 and the fluid discharge port 61 are formed on the same plane as in the prior art, however, a degree of freedom in design is reduced and location and the number of both the fluid supply ports and fluid discharge port are restricted.
Especially, from the fluid discharge port, drain water resulting from condensation of steam is discharged from an inside of the bladder. For quick discharge, it is preferable to increase an area of the fluid discharge port to thereby increase a discharge capacity.
From the fluid supply ports, on the other hand, a heated steam or the like is spouted into the bladder. In order to quickly and uniformly fill the heated steam into the bladder, it is preferable to form a large number of equally spaced fluid supply ports.
In other words, to reduce a cycle time of a tire vulcanizing step and to increase productivity, it is necessary to quickly discharge the drain water from the fluid discharge port and to quickly and uniformly fill the heated steam or the like into the bladder from the fluid supply ports.
The present invention is made for the purpose of solving the prior-art problems mentioned above and accomplishes quick discharge of the drain water by increasing the area of the fluid discharge ports to thereby increase the discharge capacity.
Moreover, the number of fluid supply ports is increased and the ports are spaced equally to thereby quickly and uniformly fill the heated steam or the like into the bladder.
In this way, it is an object of the invention to provide the fluid supply/discharge head of the bladder in the tire vulcanizing machine in which the cycle time of the tire vulcanizing step is reduced to thereby increase productivity.